Apparatus for circuit board insertion-extraction

ABSTRACT

An apparatus for facilitating the insertion and extraction of a PC board into and from a card cage, comprising a mounting body, an engager, and an actuator. In a preferred embodiment, the apparatus has a ring-shaped mounting body having a clearance hole therethrough. The apparatus is sliadably and rotatably mounted on a cylindrical rod through the clearance hole such that the apparatus is slidably rotatable along the length of the cylindrical rod. In operation, the engager is positioned in physical contact with the PC board in a notch in the board such that when a force is applied to the actuator, the engager is effected to urge the board to move in the direction of the force.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application Ser. No.09/777,369 filed on Feb. 5, 2001 entitled “Apparatus for Circuit BoardInsertion and Extraction”.

BACKGROUND OF THE INVENTION

[0002] Printed circuit (PC) boards or cards are well known and widelyused in various electrical applications. Typically, a PC board comprisesa flat rectangular sheet of insulating material, such as glass-fibrereinforced resin, with a number of circuit components mounted thereonand electrical contacts along one edge of the board. It is common toassemble a plurality of PC boards in a closely-spaced parallelrelationship in an electronic chassis or card cage, which removablysupports the PC boards in parallel slots. A card cage generally containsa backplane having a plurality of electric connectors and card guides ortracks for PC boards to be inserted into the card cage. Inserting a PCboard into a card cage along a card guide so that the board's electricalcontacts mate with a connector in the backplane of the card cage seats aPC board into the backplane. A plurality of PC boards becomeinterconnected in a card cage when each PC board is fully seated intothe backplane of the card cage.

[0003] Seating a PC board into and extracting it from a card cage can bedifficult because of the tight board-to-board spacing. It is hard toapply the right amount of force in the typically small space availablefor grasping with a human hand. In addition, because of the small space,the force applied may deviate from the straight linearity, which mayimpose bending stresses on the board and cause damage to the board.

[0004] Various devices have been developed to assist insertion andextraction of PC boards into and from card cages. Many of these devicesare developed only for insertion or extraction, but not both. U.S. Pat.No. 4,403,408 to Koppensteiner, et al. describes such a device. Forthose that are capable of assisting both the insertion and extraction ofa PC board into and from a card cage, it is very often required to mountthe device onto the PC board. An example of such a device is disclosedin U.S. Pat. No. 5,506,758 to Cromwell. The mounting of a board inserteror extractor onto the board increases the width of the board, whichrenders fewer boards capable of being assembled in a card cage.Furthermore, these devices are not cost efficient because every boardwould require its own inserter or extractor.

[0005] Accordingly, there exists a need for a simple and low cost devicefor facilitating the insertion and extraction of a PC board into andfrom a card cage. The device should also be capable of facilitating theinsertion and extraction of PC boards without being attached to theboards.

FIELD OF THE INVENTION

[0006] This invention relates to apparatuses for facilitating theinsertion and extraction of circuit boards into and from a card cage.

BRIEF SUMMARY OF THE INVENTION

[0007] The present invention provides an apparatus for facilitating theinsertion and extraction of circuit boards into and from a card cage.

[0008] Generally, a PC board insertion and extraction apparatus inaccordance with the present invention comprises a mounting body, anengager, and an actuator. Preferably, the apparatus is rotatably mountedon a stationary object relative to the PC board such that the requiredinsertion or extraction leverage is provided. In operation, the engageris positioned in physical contact with the PC board in a notch in theboard such that when a force is applied to the actuator, the engager iseffected to urge the board to move in the direction of the force. Toinsert a PC board into a card cage, therefore, the engager is positionedat least partially in a notch in the PC board, and a forward force isapplied to the actuator toward the card cage, effecting the engager tourge the board into the card cage. The PC board is extracted from thecard cage when an opposite force is applied to the actuator.

[0009] In one embodiment, the PC board insertion and extractionapparatus has a ring-shaped mounting body having a clearance holetherethrough. The apparatus is slidably and rotatably mountable on acylindrical rod through the clearance hole such that the apparatus isslidably rotatable along the length of the cylindrical rod.

[0010] In a second embodiment, the mounting body is in the shape of theletter “C,” and has a clearance hole therethrough and an opening. Theapparatus is slidably and rotatably mountable on a cylindrical rodthrough the clearance hole. Preferably, a support having an extension ismounted on the rod. The extension can be mounted on a front edge of thecard cage, or on an assembly rack, or it can be extended downward to theground. The apparatus is slidable along the length of the rod by usingthe opening of the mounting body to slide the apparatus through thesupport.

[0011] In a third embodiment, the PC board insertion and extractiondevice includes a first mounting arc, a second mounting arc, an engager,an actuator, and an interlocking mechanism. The interlocking mechanisminterconnects and interlocks the mounting arcs, forming a ring-shapedmounting body having a clearance hole therethrough. The device isslidably and rotatably mountable on a cylindrical rod through theclearance hole. The device may be removed from the cylindrical rod byunlocking the interlocking mechanism and separating the mounting arcs.

[0012] In still another embodiments similar to the one immediatelyabove, the mounting arcs interlock to form a “C” shaped mounting bodyhaving a clearance hole therethrough and an opening. This deviceoperates similar to the device in the second and third embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a side view of an embodiment of the present invention.

[0014]FIG. 2 is an isometric view of an embodiment of the presentinvention.

[0015]FIG. 3 is a perspective view of a standard PC board card cageremovably supporting a plurality of PC boards in parallel slots.

[0016]FIGS. 4 and 5 illustrate the operation of an embodiment of thepresent invention.

[0017]FIG. 6 is a side view of an embodiment of the present invention.

[0018]FIG. 7 is an isometric view of an embodiment of the presentinvention.

[0019]FIG. 8 is a partial perspective view of a PC board card cage andan embodiment of the present invention.

[0020]FIG. 9 is a side view of an embodiment of the present invention.

[0021]FIG. 10 is a side view of an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022] In accordance with the present invention, a device forfacilitating the insertion and extraction of a PC board into and from acard cage generally comprises three parts: a mounting body, an engager,and an actuator. Preferably, the engager and the actuator are eachintegrally connected to the mounting body. The mounting body rotatablysecures the device on a stationary object relative to the PC board suchthat the required insertion or extraction leverage is provided. Inoperation, the engager is positioned in physical contact with the PCboard in a notch in the board such that when a force is applied to theactuator, the engager is effected to urge the board to move in the samedirection of the force. To insert a PC board into a card cage,therefore, the engager is positioned at least partially in a notch inthe PC board, and a forward force is applied to the actuator toward thecard cage, effecting the engager to urge the board into the card cage.The PC board is easily extracted from the card cage when an oppositeforce is applied to the actuator, pulling the actuator and, thus, theengager and the board away from the card cage.

[0023] In the following description of the present invention and theoperation of the embodiments, like numerals are used to designate likeparts in the figures.

[0024] Referring to FIGS. 1 and 2, a PC board insertion and extractiondevice 10 according to the present invention includes a mounting body12, an engager 13, and an actuator 14. The mounting body 12 isring-shaped and has a clearance hole 15 therethrough. The engager 13 andthe actuator 14 are each integrally connected to the mounting body 12 atconnection points 16 and 17, respectively. The engager 13 preferably hasrounded and beveled ends to facilitate engagement with a PC board. Thereis a minimum spacing between engager 13 and actuator 14, or betweenconnection points 16 and 17, for device 10 to be operated properly. Ifthe spacing between engager 13 and actuator 14 is too small, actuator 14may be jammed into the PC board during operation, which will bediscussed in detail below. Device 10 is rotatably and slidably mountedon a cylindrical rod 18 through clearance hole 15 such that device 10 isslidably rotatable along the length of the cylindrical rod 18.

[0025] The PC board insertion and extraction device 10 can beconstructed and manufactured using a variety of metals and plastics. Formetal construction, stainless steel is preferred, although other metalssuch as aluminum or copper may also be used. The device can becast-molded or machined. Plastic construction is most preferred,however, because it is most cost-effective. Preferably, injectionmolding is utilized to construct a plastic insertion and extractiondevice so that mass production may be effected at low cost.

[0026] Turning to FIG. 3, a standard PC board card cage 20 removablysupporting a plurality of PC boards 30 in parallel slots is illustrated.The card cage 20 comprises a plurality of card guides 22 and a backplane24 having a plurality of electric receiving connectors 26. Each PC board30 includes a notch 32 formed in board 30 and electric board contacts 34formed on board 30. The card guides 22 hold and guide a PC board 30 intocard cage 20. The PC board 30 is fully inserted into card cage 20 whenthe board contacts 34 mate with the corresponding receiving connector26.

[0027] Turning now to FIGS. 4 and 5, the PC board insertion andextraction device 10 operates as follows. The insertion and extractiondevice 10 is first mounted on a stationary cylindrical rod 18, whereinthe two ends of the cylindrical rod 18 are mounted on the two side wallsof card cage 20 or on an object stationary relative to PC boards 30,such as an assembly rack (not shown). To insert a PC board 30 into cardcage 20, the insertion and extraction device 10 is slid and rotatedalong the body of the cylindrical rod 18 such that the engager 13 isinserted into notch 32 in the PC board 30, forming an engaged position.A force is then applied to the actuator 14 to push the actuator 14toward the card cage 20, rotating counter-clockwise in FIG. 5. Thismotion in turn causes the engager 13 to move toward the card cage 20,urging the PC board 30 to be inserted into the card cage 20 toward thebackplane 24 until the board contacts 34 mate with the correspondingreceiving connector 26. The PC board 30 is now in the fully insertedposition.

[0028] Still referring to FIGS. 4 and 5, to extract a fully inserted PCboard 30 from the card cage 20, the insertion and extraction device 10is placed in the engaged position with the PC board 30. A force is thenapplied to the actuator 14 to pull it away from the card cage 20. Thismotion causes the engager to also move away from the card cage 20,disengaging the board contacts 34 and the receiving connector 26 andurging the PC board 30 to move away from the backplane 24. This is bestshown in FIG. 5, with the insertion and extraction device 10 rotatingclockwise and the PC board 30 moving to the right.

[0029] Turning now to FIG. 6, a PC board insertion and extraction device40 in accordance with another embodiment of the present invention isillustrated. Device 40 includes a mounting body 42, an engager 43, andan actuator 44. The mounting body 42 is shaped like the letter “C” andhas a clearance hole 45 therethrough and an opening 48. The engager 43and the actuator 44 are each integrally connected to the mounting body42 at connection points 46 and 47, respectively. The engager 43preferably has rounded and beveled ends to facilitate engagement with aPC board. Similar to device 10 in FIG. 2, there is a minimum spacingbetween engager 43 and actuator 44, or between connection points 46 and47, so that device 40 may be operated properly. Device 40 is preferablyrotatably and slidably mounted on a cylindrical rod 18 such that device40 is slidably rotatable along the length of the cylindrical rod 18.

[0030] Device 40 is designed mainly for large card cages, although itmay be used for small card cages as well. Because a large card cagewould require a long cylindrical rod 18, the cylindrical rod 18 may sagin its mid portion over time due to gravity. To prevent this potentialproblem, a support 50 having an extension 52 is preferably mounted tothe mid portion of cylindrical rod 18 as shown in FIGS. 7 and 8.Referring specifically to FIG. 8, extension 52 of support 50 ispreferably mounted to the front bottom edge of card cage 20.Alternatively, extension 52 may be mounted to an assembly rack orsimilar stationary object. In operation, device 40 can slide along thelength of the cylindrical rod 18 without being obstructed support 50 byusing opening 48 to slide device 40 through support 50. Note thatopening 48 may be created anywhere in mounting body 42, and notrestricted to the position shown in FIGS. 6-8, as long as the positionof opening 48 does not hinder the operation of device 40. Besides havingopening 48, device 40 operates just like device 10. Device 40 may alsobe used with a cylindrical rod 18 without support 50.

[0031] Referring now to FIG. 9, a PC board insertion and extractiondevice 60 in accordance with yet another embodiment of the presentinvention is illustrated. Device 60 has a two-piece design, and includesa first mounting arc 61, a second mounting arc 62, an engager 63, and anactuator 64. Mounting arcs 61 and 62 can be securely interconnected withan interlocking mechanism comprising interlock 65 and a screw 66. Theinterconnection of mounting arcs 61 and 62 form a ring-shaped mountingbody having a clearance hole 67 therethrough. Preferably, engager 63 andactuator 64 are each integrally connected to either mounting arc 61 or62. Similar to device 10 (shown in FIGS. 1, 2, 4, and 5), device 60 isrotatably and slidably mounted on a cylindrical rod 18 through clearancehole 67 such that device 60 is slidably rotatable along the length ofcylindrical rod 18. Also similar to device 10, there is a minimumspacing between engager 63 and actuator 64 so that device 60 may beoperated properly. Device 60 operates just like device 10 except device60 may be removed from cylindrical rod 18 without removing cylindricalrod 18 from card cage 20. Device 60 is removed from cylindrical rod 18by unscrewing screw 66 and separating mounting arcs 61 and 62.

[0032] Turning now to FIG. 10, a PC board insertion and extractiondevice 70 in accordance with still another embodiment of the presentinvention is illustrated. Device 70 also has a two-piece design, andincludes a first mounting arc 71, a second mounting arc 72, an engager73, and an actuator 74. Mounting arcs 71 and 72 can be securelyinterconnected with, for example, a screw 76. The interconnection ofmounting arcs 71 and 72 form a “C” shaped mounting body having aclearance hole 77 therethrough and an opening 78. Preferably, engager 73and actuator 74 are each integrally connected to either mounting arc 71or 72. Similar to device 40 (shown in FIGS. 6-8), device 70 is rotatablyand slidably mounted on a cylindrical rod 18 through clearance hole 77such that device 70 is slidably rotatable along the length ofcylindrical rod 18. Also similar to device 40, there is a minimumspacing between engager 73 and actuator 74 so that device 70 may beoperated properly. Device 70 operates just like device 40 except device70 may be removed from cylindrical rod 18 without removing cylindricalrod 18 from card cage 20. Device 70 is removed from cylindrical rod 18by unscrewing screw 76 and separating mounting arcs 71 and 72.Preferably, mounting arcs 71 and 72 are thicker in regions near actuator74, where most of the leverage force is exerted. This “gradualthickness” design may also be applied to devices 10, 40 and 60 toenhance the strength of the devices.

[0033] The present invention herein has been described with reference toparticular embodiments for the purpose of illustrating the principlesand application of the present invention. Accordingly, any and allmodifications, variations or equivalent arrangements which may occur tothose skilled in the art are to be considered to be within the spiritand scope of the present invention as defined by the appended claims.

What is claimed is:
 1. A device for facilitating the insertion andextraction of a PC board into and from a chassis, comprising: a firstmounting arc; a second mounting arc; an engager attached to the firstmounting arc; an actuator attached to the first mounting arc; and aninterlocking mechanism, wherein the interlocking mechanism interlocksthe first and second mounting arcs.
 2. The device of claim 1, whereinthe actuator is attached to the second mounting arc.
 3. The device ofclaim 1, wherein there is a minimum spacing between the engager and theactuator.
 4. The device of claim 3, wherein the first and secondmounting arcs interlock to form a ring-shaped mounting body having aclearance hole therethrough.
 5. The device of claim 4, furthercomprising a cylindrical rod slidably coupled to the mounting bodythrough the clearance hole, wherein the mounting body is slidablyrotatable along the length of the rod.
 6. The device of claim 5, whereinthe engager and the actuator are each integrally connected to themounting body.
 7. The device of claim 3, wherein the first and secondmounting arcs interlock to form a “C” shaped mounting body having aclearance hole therethrough and an opening.
 8. The device of claim 7,further comprising a cylindrical rod slidably coupled to the mountingbody through the clearance hole, wherein the mounting body is slidablyrotatable along the length of the rod.
 9. The device of claim 8, whereinthe engager and the actuator are each integrally connected to themounting body.
 10. A device for inserting and extracting PC boards,comprising: a ring-shaped mounting body having a clearance holetherethrough, a first connection point and a second connection point; anengager attached to the mounting body at the first connection point; anactuator attached to the mounting body at the second connection point;and a cylindrical rod, wherein the mounting body is rotatably mounted onthe cylindrical rod and is slidable along the length of the rod, andwherein there is a minimum spacing between the first and secondconnection points.
 11. An electric system comprising: a chassiscomprising: a plurality of card guides and a backplane having aplurality of electric receiving connectors, the chassis having two sidewalls and an open front; and a cylindrical rod having two ends eachmounted to one side wall near the open front.
 12. The electric system ofclaim 11, further comprising a plurality of PC boards each comprising afront edge, a side edge perpendicular to the front edge, and a notchformed in the board near the front edge and the side edge.